混沌直接序列扩频信号盲解调的硬件电路实现

Hardware implementation for blind demodulation method for chaotic direct sequence spread spectrum signals

提出了基于现场可编程门阵列(FPGA)技术的混沌直接序列扩频信号盲解调的硬件电路实现方法.设计了混沌直接序列扩频信号发射机与接收机.发射机可产生10种不同的混沌直接序列扩频信号.为方便接收机的硬件电路实现,对无先导卡尔曼滤波混沌拟合盲解调算法进行了简化,在简化模型的基础上设计了接收机硬件结构.提出了一种动态调整偏移因子的新方法,使接收机能实时适应混沌映射的变化.通过高斯白噪声信道及多径信道条件下的盲解调实验,验证了盲解调算法硬件实现的抗噪声与抗多径性能,以及对10种不同的混沌直接序列扩频信号的自适应破译效果.

In this paper, we design a field-programmable gate array （FPGA）-based hardware implementation for blind demodulation method for chaotic direct sequence spread spectrum （CD3S） signals. Both transmitter and receiver aredesigned. The transmitter can produce ten chaotic maps as the spreading sequence. In the receiver, the mathematic model of unscented Kalman filter （UKF） chaotic fitting is built and simplified for hardware implementation. The hardware structure of the receiver is based on this simplified model. For real time fitting different chaotic maps, a dynamic adjustment strategy of range-differentiating factor is proposed. The additove white Gausian noise （AWGN） and multipath channel experiments verify the anti-noise and anti-multipath performance of the UKF chaotic fitting method on one hand. On the other hand, the experiments verify the method can demodulate CD3S signals spread by all ten chaotic maps effectively.